WIW: RB "906" heads

MoparMike1974 said

If its a 6 then its a casting flaw. The loop is completely closed in.

Click to expand...

Give it a few good rakes w/a wire brush, it'll pop. Plus the upper/lower loop proportions are the first clue, top is distinctly smaller, an "8" is near or identical top & bottom. Good luck with the sales!